Egg Production Traits Research Articles

Egg production and quality assessment of Nigerian indigenous chicken genotypes and their crosses with Marshall

This study focused on investigating the reproductive performance of Nigerian indigenous chickens and their crosses with Marshall. The genotypes were normal-feathered (Nn), frizzle-feathered (Ff) and naked neck (Na) chickens, while the crossbreds with Marshall (M) breed were MNn, Mf and MNa respectively (Marshall being the sire while the indigenous are dams). Data were taken on; weekly egg production, weight at first egg and age at first egg. Genotype significantly (P<0.05) influenced egg production traits. Egg weight ranged from 23.71±21.06g to 26.13±0.94g for indigenous purebreds and 39.75±0.75 to 48.06±0.579 for crossbreds. Age at first egg were 165.63±0.61 days (Nn), 170.60±0.75 days (Na) and 173.57±0.52 days (Ff) 188.77±1.67 days (MNn), 187.50±3.16 days (MNa) and 185.25±5.44 days (MF). Also, genotype significantly (P<0.05) influenced egg quality traits. Heritability for first egg production traits were 0.37 (Nm), 0.16 (Na) and 0.66 (Fz) while heritability estimates for egg quality trait (haugh unit) were 0.14, 0.07 and 0.08 for Nm, Na and Fz birds, respectively. The crossbreds performed better than the indigenous purebreds in egg production traits. The Nigerian indigenous chicken can therefore be improved upon for better egg production traits using the Marshall breed.

Growth and Early Laying Performance of Pullet Chickens Fed Sorghum Based Diets Supplemented with Enzymes

A study was carried out to evaluate the effect of replacing maize with sorghum and supplementation with enzymes, on the growth and laying performance of laying chickens. Four hundred and fifty 12-weeks old Lohman Brown pullets were distributed randomly into six dietary treatments with three replicates per treatment, each replicate had 25 birds with uniform group weights at the initial stage of the study. The treatments included maize without enzymes (T1) and sorghum without enzymes (T2) as two controls respectively, while T3, T4, T5, and T6 contained sorghum based diets with phytase, protease, roxazyme G2G, and a combination of protease and roxazyme G2G respectively. The experiment lasted from 12 to 32 weeks of age of birds during which data were collected on growth and early egg laying performance of birds. Data obtained were subjected to analysis of variance, using the completely randomized design (CRD). Significant differences among treatment means were compared using the Tukey test. Significant (p<0.05) differences were noted in final weight (g/bird), weight gain (g/bird), daily weight gain (g/bird), total feed intake (g/bird), daily feed intake (g/bird/day), and feed to gain ratio. Final weight and weight gain were significantly (p<0.05) better for birds in T4 (sorghum + protease) compared to the other treatments, but was similar to T1 (control). At the early laying stage, no definite trend was observed among the egg production traits. However, dietary treatment supplemented with phytase (T3) had the highest numerical values for; weight of first egg (54.28g), number of eggs at peak lay (24.00), hen house egg production 78.84%, and hen day egg production, 81.09%. It was concluded therefore, that sorghum with phytase and protease supplementations can be used in layers' diets for optimum egg production. It is recommended that phytase supplementation at 0.02% with sorghum can be incorporated into the diets of egg type chickens for optimum performance.

Performance of Laying Hens Fed Sorghum Based Diets Supplemented with Enzymes

Sorghum is the primary alternative feedstuff for corn in some developed countries in the production of poultry. Thus, four hundred and fifty 32 weeks old Lohmann Brown laying hens were used in a study to evaluate the effect of replacing maize with sorghum with or without enzymes supplementation, on egg laying performance and egg quality characteristics of laying hens. Birds were distributed randomly into six dietary treatments with three replicates per treatment, each replicate had 25 birds with uniform initial group weights. The treatments included maize without enzymes (T1); sorghum without enzymes (T2); as controls respectively, while T3, T4, T5, and T6 contained sorghum based diets with phytase, protease, G2G, and a combination of protease and G2G respectively. Laying performance, cost of production, and egg quality characteristics were determined for the period of the trial, 33-56 weeks of age of the birds. All data obtained were subjected to analysis of variance, using the completely randomized design (CRD) and significant differences among treatment means were compared using the Tukey test. Significant (p<0.05) differences were observed among dietary treatments but with no defined trend observed for egg production traits. Daily feed intake was significantly (p<0.05) higher in maize control diet compared to the other treatments. Diets supplemented with phytase (T3), protease (14), and combination of protease and roxazyme G2G (T6) had significantly (p<0.05) better feed conversion ratio with T3 having the lowest value of 4.01 compared to the other treatments. For feed cost/dozen egg (N), Kg feed/dozen eggs, income above feed cost at N30 per egg, and income above control treatment; phytase (T3), protease (T4), roxazyme 626 (T5), and protease + roxacyme G2G (T6) diets in this study showed better performance than the control. Sorghum diet without enzyme had significantly (p<0.05) least performance for egg number. Hen housed egg production (HHP) and hen day egg production (HDP) compared to the other treatments while sorghum diet with phytase had the highest value (60.12g/day) for average egg weight compared to the other treatments. Egg quality characteristics showed the best performance for dietary treatments supplemented with phytase (T3) in all the other parameters considered, apart from the albumen height, yolk diameter, and yolk index. It was concluded therefore, that sorghum with phytase and protease supplementations can be used in layers' diets as a substitute for maize for optimum egg production.

Genetic and phenotypic assosiations of juvenile body weights and egg production traits in two strains of Rhode Island chickens

Genetic and phenotypic assosiations of juvenile body weights and egg production traits in two strains of Rhode Island chickens

Determination of relative economic weights of growth and egg production traits in Nigerian indigenous chicken

The relative economic weight (REW) of a trait is the additional gain/loss from a unit change in the trait relative to other traits in an individual. They are used to calculate aggregate economic values for purposes of genetic improvement in animals. The present study was designed to evaluate the bio-economic variables of growth and 16 weeks egg production parameters: egg number (EN16) egg weight (EWT16) body weight at first egg (BWTFE), body weight at 16 week of lay (BWTE16), cost of feed, and revenue from eggs and chicken carcass, 16 feed conversion ratio (FCR ), and body weight gain (BWG16) in the Nigerian indigenous chicken, and to determine the economic weights (EW) and REW of EN16, EWT16 and BWTE16 for G0, G1, and G2 generations. A total of 250 pullets (20 week old, point of lay) from a population of heavy body weight local chickens were used for the study. The birds were housed individually in cages, fed optimally on layers mash (G and G : 100g/bird/day; G : 0 1 2 125g/bird/day) and given water ad libitum. Data included EN , EWT , BWTE , BWTFE, 16 16 16 and prices of feed, eggs and spent hens, FCR , and BWG . Data on EN , EWT , BWTE , 16 16 16 16 16 and BWTFE were compared across generations using ANOVAand with other variables were used to generate the EW of the traits. The EW were then standardized relative to that of BWTE . Results showed that EW and REW of EN , EWT , and BWTE were 7.47 and 3.15, 16 16 16 16 13.67 and 5.77 and -2.37 and -1.00, respectively in G ; 13.07 and 3.82, 23.69 and 6.93, and - 0 3.42 and -1.00, respectively in G ; 16.80 and 2.89, 30.75 and 5.28 and -5.82 and -1.00, 1 respectively in G generation. Thus EN and EWT enhanced while BWTE depressed the 2 16 16 16 worth of the hen as a layer. EWT was more important than EN and both were more 16 16 important than BWTE economically. Therefore, EWT and EN are the major bio-economic 16 variables of the local hen as an egg chicken.

Egg production and quality assessment of Nigerian indigenous chicken genotypes and their crosses with Marshall

This study focused on investigating the reproductive performance of Nigerian indigenous chickens and their crosses with Marshall. The genotypes were normal-feathered (Nn), frizzle-feathered (Ff) and naked neck (Na) chickens, while the crossbreds with Marshall (M) breed were MNn, MFf and MNa respectively (Marshall being the sire while the indigenous are dams). Data were taken on; weekly egg production, weight at first egg and age at first egg. Genotype significantly (P<0.05) influenced egg production traits. Egg weight ranged from 23.71±1.06g to 26.13±0.94g for indigenous purebreds and 39.75±0.75g to 48.06±0.57g for crossbreds. Age at first egg were 165.63±0.61 days (Nn), 170.60±0.75 days (Na) and 173.57±0.52 days (Ff), 188.71±1.67 days (MNn), 187.50±3.16 days (MNa) and 185.25±5.44 days (MFf). Also, genotype significantly (P<0.05) influenced egg quality traits. Heritability for first egg production traits were 0.37 (Nm), 0.16 (Na) and 0.66 (Fz) while heritability estimates for egg quality trait (haugh unit) were 0.14, 0.07 and 0.08 for Nm, Na and Fz birds, respectively The crossbreds performed better than the indigenous purebreds in egg production traits. The Nigerian indigenous chicken can therefore be improved upon for better egg production traits using the Marshall breed.

Growth and Early Laying Performance of Pullet Chickens Fed Sorghum Based Diets Supplemented with Enzymes

A study was carried out to evaluate the effect of replacing maize with sorghum and supplementation with enzymes, on the growth and laying performance of laying chickens. Four hundred and fifty 12-weeks old Lohmann Brown pullets were distributed randomly into six dietary treatments with three replicates per treatment, each replicate had 25 birds with uniform group weights at the initial stage of the study. The treatments included maize without enzymes (T1) and sorghum without enzymes (T2) as two controls respectively, while T3, T4, T5, and T6 contained sorghum based diets with phytase, protease, roxazyme G2G, and a combination of protease and roxazyme G2G respectively. The experiment lasted from 12 to 32 weeks of age of birds during which data were collected on growth and early egg laying performance of birds. Data obtained were subjected to analysis of variance, using the completely randomized design (CRD). Significant differences among treatment means were compared using the Tukey test. Significant (p<0.05) differences were noted in final weight (g/bird), weight gain (g/bird), daily weight gain (g/bird), total feed intake (g/bird), daily feed intake (g/bird/day), and feed to gain ratio. Final weight and weight gain were significantly (p<0.05) better for birds in T4 (sorghum + protease) compared to the other treatments, but was similar to T1 (control). At the early laying stage, no definite trend was observed among the egg production traits. However, dietary treatment supplemented with phytase (T3) had the highest numerical values for; weight of first egg (54.28g), number of eggs at peak lay (24.00), hen house egg production 78.84%, and hen day egg production, 81.09%. It was concluded therefore, that sorghum with phytase and protease supplementations can be used in layers' diets for optimum egg production. It is recommended that phytase supplementation at 0.02% with sorghum can be incorporated into the diets of egg type chickens for optimum performance.

Performance of Laying Hens Fed Sorghum Based Diets Supplemented with Enzymes

Sorghum is the primary alternative feedstuff for corn in some developed countries in the production of poultry. Thus, four hundred and fifty 32 weeks old Lohmann Brown laying hens were used in a study to evaluate the effect of replacing maize with sorghum with or without enzymes supplementation, on egg laying performance and egg quality characteristics of laying hens. Birds were distributed randomly into six dietary treatments with three replicates per treatment, each replicate had 25 birds with uniform initial group weights. The treatments included maize without enzymes (T1); sorghum without enzymes (T2); as controls respectively, while T3, T4, T5, and T6 contained sorghum based diets with phytase, protease, G2G, and a combination of protease and G2G respectively. Laying performance, cost of production, and egg quality characteristics were determined for the period of the trial, 33 -56 weeks of age of the birds. All data obtained were subjected to analysis of variance, using the completely randomized design (CRD) and significant differences among treatment means were compared using the Tukey test. Significant (p<0.05) differences were observed among dietary treatments but with no defined trend observed for egg production traits. Daily feed intake was significantly (p<0.05) higher in maize control diet compared to the other treatments. Diets supplemented with phytase (T3), protease (T4), and combination of protease and roxazyme G2G (T6) had significantly (p<0.05) better feed conversion ratio with T3 having the lowest value of 4.01 compared to the other treatments. For feed cost/dozen egg (N), Kg feed/dozen eggs, income above feed cost at N30 per egg, and income above control treatment; phytase (T3), protease (T4), roxazyme G2G (T5), and protease + roxazyme G2G (T6) diets in this study showed better performance than the control. Sorghum diet without enzyme had significantly (p<0.05) least performance for egg number, Hen housed egg production (HHP) and hen day egg production (HDP) compared to the other treatments while sorghum diet with phytase had the highest value (60.12g/day) for average egg weight compared to the other treatments. Egg quality characteristics showed the best performance for dietary treatments supplemented with phytase (T3) in all the other parameters considered, apart from the albumen height, yolk diameter, and yolk index. It was concluded therefore, that sorghum with phytase and protease supplementations can be used in layers' diets as a substitute for maize for optimum egg production.

Interrelationships existing between body weight and egg production traits in Olympia Black layers

Forty 76 weeks old Olympia Black layers were randomly selected, individually caged and intensively reared for a period of 16 weeks to study the effect of body weight on some egg production traits. The analysis of variance revealed significant effect of body weight on production traits investigated (P 0.05). The correlation analysis showed that the body weight was positively and non-significantly (P>0.05) correlated with egg length, egg breadth, shell weight, yolk weight, albumen weight, shell thickness and significantly with egg weight, (P<0.01) and negatively with egg index (r = 0.016). The second-degree (quadratic) equations for estimates of optimum 76 week body weights suggested 1.271 to 1.801 as required body weight range in kilograms for satisfactory performance. The body weight range at this age is attainable through breeding, good feeding and other management practices. Keywords: Olympia black layer, body weight, egg traits, second-degree equation, interrelationships.

INTERRELATIONSHIP EXISTING BETWEEN BODY WEIGHT AND EGG PRODUCTION TRAITS IN OLYMPIA BLACK LAYERS

Forty 76 weeks old Olympia Black layers were randomly selected, individually caged and intensively reared for a period of 16 weeks to study the effect of body weight on some egg production traits. The analysis of variance revealed significant effect of body weight on production traits investigated (P&lt;0.01) except egg index (P&gt;0.05). The correlation analysis showed that the body weight was positively and non-significantly (P&gt;0.05) correlated with egg length, egg breadth, she'll weight, yolk weight, albumen weight, she'll thickness and significantly with egg weight (P&lt;0.01) and negatively with egg index (r = 0.016). The second-degree (quadratic) equations for estimates of optimum 76 week body weights suggested 1.271 to 1.801 as required body weight range in kilograms for satisfactory performance. The body weight range at this age is attainable through breeding, good feeding and other management practices.

Genetic parameters for egg production traits in crosses between local and exotic chickens estimated by Bayesian inference

Estimates of genetic parameters for economic traits are important to enable the breeder estimate the breeding value of individuals available for selection. Thus, this study was carried out to estimate genetic parameters namely heritability and genetic correlations among egg production traits in two strain crosses using bivariate animal model in Bayesian (MCMC) method. The egg production data were obtained from four generations which comprised the base population of two commercial egg strains and the local chicken, the inbred population derived from the base population, the F1 crossbred population obtained from the crossing of the local and exotic inbred chickens and the backcross population obtained from the backcrossing of the crossbred to their parents. A total number of 1,138 daughters of 62 sires and 620 dams were used for the study. The autocorrelations among samples in the MCMC chain were less than 0.1 for all lag values indicating that all samples of the posterior distribution were independent. The estimated heritability for age at first egg, body weight at first egg, hen day egg number, weight of first egg, egg weight at thirty week and egg weight at forty week were 0.62, 0.48, 0.47, 0.53, 0.54 and 0.56 for strain 1 crosses and 0.43, 0.48, 0.49, 0.52, 0.52 and 0.53 for strain 2 crosses. The corresponding highest posterior density interval ranged from 0.22 to 0.91 for strain 1 crosses and 0.07 to 0.83 for strain 2 crosses. The genetic correlations among egg production traits ranged from 0.06 to 1.97 in strain 1 and 0.06 to 2.59 in strain 2 crosses. The estimates were within the range reported in literature for egg production traits in chicken and imply that appreciable amount of additive genes exist in the strain crosses which could be used for the selection of superior birds. The magnitude of genetic correlations implies that selection of one trait could lead to correlated response to the other traits.

Heterosis for egg production in native by exotic by inbred chicken crosses

Inbred lines generated from the native and exotic chickens were compared with their F1 and backcross populations for a range of short term egg production traits. The experimental birds were brooded for 8 weeks and raised on a deep litter pens from 8 to 40 weeks of age. Age at first eggs were longer in the crossbred groups and the delay was mostly caused by the dominant genes from the exotic parents. Highly significant (P&gt;0.01) heterosis were obtained by the crossbred groups in hen day rate and total egg mass respectively. The heterosis observed in the crossbred groups for egg weight was low and mostly non significant. the backcross groups recorded residual heterosis in egg production traits ( hen day rate, total egg mass and egg weight) and the magnitude was higher in the exotic than the native backcrosses. The results further indicate that the egg production performance of the crossbred groups were mostly influenced by maternal, sex linked, dominance and epistatic gene effects. It was suggested that the egg production potential of the native chicken could be improved further by cross mating-selected native and exotic backcross groups. This should be followed by crisscrossing.

Single Nucleotide Polymorphisms of Candidate Genes Related to Egg Production Traits in Vietnamese Indigenous Chickens

The objective of this work was to detect single nucleotide polymorphisms (SNPs) in two candidate genes known to relate with reproductive traits in Vietnamese chicken. Two indigenous breeds Ri and Mia chickens were used for genotyping 4 SNPs namely intron 1 of growth hormon gene (GH), exon 5 of prolactin receptor gene (PRLR5), a 24 bp nucleotide sequence insertion-deletion at situation -358 in 5’- untranslated region of prolatin gene (PRL24); and at site C2404T of prolactin gene (PRL2402). It was shown that the SNP sites of these candidate genes were identified in two local breeds. Three genotypes of each loci were found (AA, AB and BB for GH; II, ID and DD for 24 bp indel of PRL and CC, CT and TT for PRL2402), except only genotypes of AA and BB of PRLR5 were detected (no heterozygous genotype of AB). The frequencies of the desired genotypes of AA (GH), BB (PRLR5), II (PRL24) and CC (PRL2402) were low in both indigenous Ri and Mia chickens. Based on this study it could be suggested that the study on association between these loci with egg production traits and the selection to increase the desired genotype frequency in poputions are necessary to improve egg production of Ri and Mia chickens.

Nutritional impacts of using graded levels of dietary linoleic acid on egg production, egg quality, and yolk fatty acid profile of laying ducks

There is an increased interest among poultry nutritionists to increase the linoleic acid (LA) content of the egg, which possesses many benefits for human health. This fatty acid must be provided by the diet as the bird’s body cannot synthesise it. The present study evaluated the influence of different levels of dietary LA on the productive performance, egg quality and yolk lipid profile of Longyan laying ducks. In total, 900 Longyan female laying ducks aged 24 weeks were assigned to six dietary treatments, each containing 6 replicates of 25 ducks. The six dietary treatments contained six incremental levels of LA (analysed content: 0.36, 0.66, 0.80, 1.07, 1.28, and 1.45%) and the experimental diets were offered for the following 20 weeks. The results showed that different supplemental levels of dietary LA had no effects on egg production traits, concentrations of plasma cholesterol and triglycerides, or low or high-density lipoprotein cholesterol (p > .05). There was a linear increase in yolk colour (p < .001) and yolk cholesterol (p < .005) with increasing dietary LA. With increased intake of LA, the yolk content in C18:1, C20:1 and total monounsaturated fatty acids decreased linearly (all p < .005), but the concentrations of C18:2, C18:3, C20:2, C20:3, C20:4, C20:6, and total polyunsaturated fatty acids were linearly increased (p <.008 to <.0001). The results of the present work show that LA dietary supplementation of Longyan duck layers positively modified the yolk fatty acid profile, increased the yolk cholesterol, and enhanced the yolk colour. HIGHLIGHTS Linoleic acid (LA) is an essential fatty acid that must be added to the poultry diet. This study evaluated six dietary levels of linoleic acid in laying ducks. LA dietary supplementation modified yolk colour, cholesterol and fatty acid profile.

Effect of digestible threonine on performance, egg quality, blood metabolites, and immune responses in laying hens fed a wheat-based diet in the second cycle

The current experiment was conducted to evaluate the effects of digestible threonine (dThr) on performance, egg quality, blood metabolites, and immune responses in laying hens fed a wheat-based diet during the second cycle. Also, dThr requirements were determined based on nutrient dose-response data. A total of 384, 105-week-old post-molt Hy-line-W36 laying hens were allocated to six groups, 0.02% increments, ranging from 0.44 to 0.54% dThr, with eight replicates/treatment and eight birds each, from 105 to 116 wk. By increasing, dThr levels improved egg weight with a linear trend (p <.01), and egg production (EP), egg mass (EM), and feed conversion ratio (FCR) with quadratic trends (p <.05). Hens fed diet contained 0.48% dThr, dThr/digestible Lys (dLys) of 66% showed the best egg production traits. However, feed intake, egg quality traits, blood metabolites, and immune responses were unaffected by dThr levels. Based on the quadratic broken‐line regression models, the dThr requirements of laying hens during the second production cycle for optimised the EP, EM, and FCR were estimated at 507, 514, and 520 mg/hen per day, respectively. These values correspond to 9.84–10.1 mg/g of EM. It is concluded, in the laying hens fed a wheat-based diet during the second cycle, the dietary dThr level of 0.48%, dThr/dLys of 66%, and a daily intake of 520 mg dThr/bird are adequate for optimised performance. The amino acids requirements of laying hens vary depending on trait is considered for optimisation. The dThr requirement estimated for FCR was higher than those for EP and EM. HIGHLIGHTS In the laying hens that feed a wheat-based diet during the second cycle. A dietary digestible threonine concentration of 0.48% and a daily intake of digestible threonine 520 mg/bird are adequate for optimised performance.

Advances in genetic selection and breeder practice improve commercial layer hen welfare

Modern commercial layer breeds represent the culmination of ~7000 years of natural genetic selection. This selection was driven in former times by a combination of genetic-shift and -drift events, that led to chickens being favoured as domesticated species for meat and egg production. More recently, in the early 20th century, the concept of hybrid vigour was discovered and accelerated the natural breeding progress that delivered new genetic lines and more favourable production traits. In the mid-20th century, the broiler-type and egg layer-type lines diverged and, in the 21st century, genetic analysis has further accelerated the progress made towards extended primary breeding characteristics such as egg quality, production and feed-intake traits, together with secondary breeding characteristics such as behavioural traits that have improved robustness in different housing systems, climates and feed types, which together have significantly improved welfare traits. Most recently, there has been the adoption of higher-powered computational analytics together with quantitative trait loci and single-nucleotide polymorphism assessment, which have further improved the uniformity of production traits within breeds. Most importantly, this has provided the primary breeding companies with improved and broader basis of selection of the modern commercial layer breeds, which also improved the alignment of layer strains with market requirements, and diverse variations in housing, nutritional and environmental conditions. This is also testament to the speed with which the commercial layer geneticists can respond to changing welfare policy on factors such as stocking density and beak treatment. The present paper reviews the modern approaches to genetic selection, including considerations of and benefits to the welfare state of commercial layers.

Effect of season and different dietary protein level on production and reproductive performance and egg characteristics of indigenous Guinea fowl (Numida meleagris) in the middle belt of Ghana

This study was undertaken to determine the impact of seasonal variations and different dietary protein levels on production traits, reproductive performance and egg characteristics of Guinea fowl (Numida meleagris) in the Middle belt of Ghana. Twelve (12) males and forty-eight (48) females Pearl Guinea fowls of 12 weeks of age were subjected to isocaloric diet containing 16%, 18%, 20% and 22% crude protein levels.Each group was replicated three times and reared in three seasons (Dry-December-March, Major rains-April-July and Minor rains-August-November) in a 3x4 factorial experiment. Data were analyzed using General Linear Model procedure of SAS.Hen day egg production (HDEP) and egg mass increased (p&lt;0.05), but feed intake, feed conversion ratio, egg weight, fertility and hatchability of incubated eggs were not significantly different (p&gt;0.05) with increasing dietary protein. Egg quality traits did not differ significantly (p&gt;0.05) except egg yolk (p&lt;0.05). Season showed positive (p&lt;0.05) relationship with all production traits as well as fertility of incubated eggs, but not hatchability (p&gt;0.05). Egg internal and external traits were significantly (p&lt;0.05) influenced by season except yolk weight and shell weight (p&gt;0.05).Results demonstrates that increasing dietary protein promoted egg production and reproductive traits in Guinea fowl, nevertheless, 16% crude protein diet is sufficient to support optimum egg production, fertility and hatchability, and egg characteristics. Rainy seasons countenance production traits, fertility and hatchability as well as egg characteristics, thus, breeding should be planned to take advantage of the major rainy season.

Effects of Light Stimulation Age on Body Weight and Egg Production Traits of Broiler Pure-lines in the Laying Period

In this study, the effects of light stimulation at normal (NLS: 154 days) and early (ELS: 140 days) age on some physiological and reproductive traits in dam and sire broiler pure-lines were carried out during the laying period. The study was conducted with A1, A2, A3, A4 dam lines and B1, B2 sire lines up to 43 weeks of age, whose breeding studies were carried out in Eskişehir Geçit Kuşağı Agricultural Research Institute. Live weight and feed consumption were determined during the growing period. In the laying period, in addition to these, the first laying age, 50% yield age, egg yield, hatching egg yield and egg weight were determined. The data obtained were evaluated according to light stimulation age and pure-lines by two factor analysis of variance. NLS and ELS treatments did not significantly affect the body weights of the pure-lines at 20, 24 and 43 weeks of age. However, differences were found significant in terms of body weight at 20, 24 and 43 weeks of age in pure-lines. Lines reached the first laying age at 172 days in NLS, and at 165 days of age in ELS. The 50% yield age was realized at 184 d and 176 d of age in parallel with the first laying age. The effects of light stimulation age on egg yield and hatching egg yield were found significant. In NLS treatment all pure-lines, 5 more eggs were produced in egg yield and hatching egg yield. However, differences in egg yield and weight in pure-lines were found significant. The study results showed that the egg production can be increased by first light stimulation at the 20 weeks of age, provided that at least 2 kg live weight is achieved in broiler pure-lines.

Molecular Breeding of Three Genes Associated with Egg Production Traits in Three Strains of Chickens

Molecular Breeding of Three Genes Associated with Egg Production Traits in Three Strains of Chickens

Growth response, carcass characteristics and egg laying performance of Japanese quail (Coturnix coturnix japonica ) fed diets containing varying levels of fermented cassava (Manihot esculenta ) peel meal

A two phased experimental study was conducted on 300, two-weeks-old Japanese quails to determine the effect of feeding diets containing varying levels of fermented cassava (Manihot esculenta ) peel meal on the growth performance, carcass characteristics and egg production of Japanese quail ( ). Japanese quails with mean initial body weight of 26.67 g and of mixed sexes were used. Fermented cassava peel meal (FCPM) was prepared by soaking fresh cassava peels in water (that is twice its weight) for three days. Thereafter, the peels were put in a jute bag and kept for 12 hours under a hydraulic press; sundried for a few days and milled using an attrition mill. During the growing phase, the birds were randomly allotted to four dietary treatments with 75 birds per treatment, each replicated three times, with the diets containing FCPM replacing 0, 25, 50 and 75 % maize to form diets T , T , T and T respectively. The diets were isonitrogenous, containing 24 % crude protein, and fed to the experimental birds for six weeks. Data were collected on feed intake, growth performance and carcass characteristics. The laying phase involved 120 female quails from he growing phase that were sexed to retain only the females. They were then allotted to four dietary treatments of three replicates per treatment; with 10 birds per replicate. The birds were fed the experimental diets containing FCPM replacing 0, 25, 50 and 75 % maize for eight weeks, and data were collected on egg production and egg quality parameters. Results show significant (p&lt;0.05) differences in daily feed intake and nutrient digestibility among the treatments, while daily weight gain and feed conversion ratio (FCR) were not significantly (p&gt;0.05) different, during the growing phase. For the laying phase, there were no significant (p&gt;0.05) differences in daily feed intake, hen day production (HDP) and all the egg quality traits determined. Therefore, it can be concluded that dietary maize could be replaced with FCPM up to 50 % and 75 % in growing quails without any deleterious effects on growth performance and carcass characteristics respectively; whereas it can replace up to 75 % in the diet of laying Japanese quails without any adverse effect on egg production and egg quality traits.